In the processing of many fabrics, including particularly but not limited to tubular knitted fabrics, it is advantageous to effect mechanical compressive shrinkage of the fabric as part of the finishing procedure, in order to compensate for the tendency of the fabric otherwise to shrink in the lengthwise direction as a result of normal washing and drying. Particularly advantageous equipment and procedures for this purpose are reflected generally in the Eugene Cohn et al. U.S. Pat. Nos. 3,015,145, 3,015,146 and 3,083,435. The Diggle U.S. Pat. No. 3,973,303 is directed to improved arrangements for operating and adjusting such equipment.
In general, mechanical compressive shrinkage of the type referred to includes a pair of feeding and retarding rollers arranged in opposed relation to form a nip through which fabric is directed. The respective feeding and retarding rollers are individually driven and controlled, such that the peripheral speed of the retarding roller is arranged to be less by predetermined amount than the peripheral speed of the feeding roller. A confining shoe is arranged for cooperation with the feeding roller such that incoming fabric is lightly urged against the surface of the feeding roller in order to provide a substantially positive feed of the fabric. Pursuant to known principles, the confining shoe terminates a short distance (e.g., six mm) upstream from the narrowest portion of the roller nip. In this short zone, the fabric undergoes a transition from its feeding speed, at the entry end of the zone, to its retarded speed, at the discharge end of the zone. The fabric is thus compressed lengthwise, under highly controlled conditions within the short zone, and then subjected to heat and rolling pressure as the fabric passes through the roller nip.
In the apparatus described, the confining shoe performs a critical function, and precise alignment and adjustment of the shoe is important. Moreover, the confining shoe has constituted a costly element of the equipment, because of the need for precise and complex contouring and shaping of the shoe over a rather substantial length. In the operation of the equipment, damage to the confining shoes is sometimes experienced as a result of careless operation, warpage of the shoe through uneven heating, etc. sometimes necessitating time consuming and expensive repair or replacement of the shoe.
In accordance with the present invention, a novel and improved confining shoe construction is provided which, at one time, enables a significant reduction in the initial manufacturing cost, improved operating performance, and greater convenience and facility in repair and maintenance. More particularly, in the apparatus of the invention, the confining shoe includes a heavy, rigid primary support beam arranged to extend over the full width of the machine. A plurality of individual, contoured shoe segments, are secured in side-by-side relation across the width of the beam and, collectively, provide a contoured surface corresponding substantially to the desired contours of the confining shoe. In conjunction with the several individual shoe segments, there is provided a single, continuous, contoured liner member, which conforms closely to the working contours of the shoe segments, and the outer surface of which forms the working surface of the confining shoe.
In the construction of a confining shoe in accordance with known techniques, it has been customary to mount at the extremity of the confining shoe a short, thin blade, which can extend between the feeding and retarding rollers, to a position close to but spaced a short distance from the working nip. In the confining shoe constructed in accordance with the present invention, the continuous, contoured liner element includes an integral portion, extending slightly beyond the extremities of the individual shoe segments and forming in effect the blade tip of the shoe.
Pursuant to the invention, the arrangement and mounting of the continuous liner element permits relatively easy removal and replacement of the liner, as may be necessary from time to time as the liner becomes worn or damaged.
In addition to realizing significant economies in initial manufacture and subsequent maintenance, the improved confining shoe construction enables a generally higher quality of production output to be achieved, because of the practical ability to maintain the equipment generally in better operating condition.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment and to the accompanying drawings.